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Aug. 23, 2010 -- Scientists report that within eight hours of drinking cranberry juice, the juice could help prevent bacteria from developing into an infection in the urinary tract.

Previous studies have suggested that the active compounds in cranberry juice are not destroyed by the digestive system after people drink them, but instead work to fight against bacteria, including E. coli. This latest study, presented at the national meeting of the American Chemical Society in Boston, affirms that and provides evidence of the medicinal value of cranberries.

The new research suggests that the beneficial substances in cranberry juice could reach the urinary tract and prevent bacterial adhesion within eight hours.

Researchers from the Worcester Polytechnic Institute in Massachusetts grew strains of E. coli in urine collected from healthy people before and after they drank cranberry juice cocktail.

How Cranberry Juice Treats Urinary Tract Infections

A mixture of cranberry juice, water, and sweeteners found in cranberry juice cocktail was used for the study because it is the most popular cranberry beverage. The researchers discovered that in petri dishes, cranberry metabolites in the juice prevented E. coli from sticking to other bacteria, limiting its ability to grow and multiply. If E. coli is able to connect with other bacteria, such as the bacteria found in the urinary tract, it forms a layer or "biofilm." This allows the bacteria to multiply and produce an infection.

"A number of controlled clinical trials -- these are carefully designed and conducted scientific studies done in humans -- have concluded that cranberry juice really is effective for preventing urinary tract infections," says study researcher Terri Anne Camesano, PhD, in a news release. "That has important implications, considering the size of the problem and the health care costs involved."

Urinary tract infections are more common among women than men. According to the researchers, one in three women has had a urinary tract infection.

Urinary tract infections can occur anywhere along the urinary tract, which includes the bladder, urethra, and ureter. These infections account for 8 million trips to the doctor's office every year and cost more than $1.6 billion to treat.

Camesano said people should not self-treat urinary tract infections, and anyone who suspects they have an infection should see a doctor, but drinking cranberry juice may be an easy, inexpensive way to help keep E. coli at bay.

In the event of a urinary tract infection, antibiotics are the most common treatment. If left untreated, particularly in children, the elderly, or people with other chronic medical conditions, urinary tract infections can become more severe.

SOURCES:News release, American Chemical Society.National Institute of Diabetes and Digestive and Kidney Diseases.